Method for Making a Stable Stacked Snack Food Configuration

ABSTRACT

A method for making asymmetrical snack pieces that can be efficiently nested or stacked. A dough preform is mated with a mold as the preform is cooked into a snack piece. The preform takes the shape of the mold. The mold is designed such that the resultant snack piece, when resting upon a flat surface, has an apex and a base of equal height. This is achieved by making the mold such that the centroid of the snack piece lies in a plane that is parallel to a plane formed by the vertices of the snack piece. The snack pieces can then be efficiently nested or stacked.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a method for making a stable stackedsnack food configuration and more particularly, to a method for making astable stacked food configuration whereby the stacked snack foodcomprises vertices that are substantially parallel to a flat restingsurface when the snack food is resting on its centroid.

2. Description of Related Art

Stacked tortilla chips are known in the art. For example, U.S. Pat. No.6,412,397, assigned to the same assignee of the present invention,discloses a method and apparatus for making stackable tortilla chipsusing a double mold form fryer.

FIG. 1 a is a schematic cross-sectional view of a double mold form fryerwith continuous top and bottom conveyors. The fryer assembly 10 has afryer housing 12 that contains conveyors for moving pre-forms throughit. A top belt 20 is disposed in a top portion of the fryer housing 12and is supported and rotated by two rollers 22, 24. A bottom belt 30 isdisposed beneath the top belt 20. The bottom belt 30 is a continuousloop belt and is supported and rotated by two rollers 32, 34. A fryerpan 50 containing a body of oil 52 is situated within the fryer housing12 so that at least a portion of the top and bottom belts 20, 30, whenadjacent to each other, are passed through the oil 52.

For cooking, pre-forms are led towards the fryer by the bottom belt 30starting at about the input-side roller 32. The pre-forms are thenfollowed from above by the top belt 20 and led towards a point in theoil 52 where the bottom belt 30 comes into close proximity with the topbelt 20. By at least this point, the pre-forms have made contact with atleast one mold surface. While not depicted, molds are commonly placed onat least the exterior surface of the top belt 20 but may also be placedon the exterior surface of the bottom belt 30. Once the pre-forms aresecured between the top and bottom belts 20, 30, which run substantiallyparallel to each other through the oil 52, they are introduced to thehot cooking oil 52 at an oil entry point 53. The pre-forms thereaftertravel through the hot oil 52 in the oil pan 50 completely submergeduntil they emerge from the oil 52 at an oil exit point 55. A typicalform fryer may be operated with an oil frying temperature between 240 to400° F.

In addition to dual mold form fryers, a single mold form fryer such asone disclosed in U.S. patent application Ser. No. 10/347,993, assignedto the same assignee as the present invention can be used. FIG. 1B is aschematic cross-sectional view of a single mold form fryer with acontinuous top conveyor. A fryer assembly 100 receives snack products tobe fried (pre-forms) at an entrance area 102. After cooking, the snackproducts exit the fryer assembly 100 on an exit conveyer 140 at an exitarea 104. Between the entrance area 102 and the exit area 104 is a fryerhousing 112 having a port 114 for controlling the fryer environmentabove the cooking snack products. The top conveyer 120 of the singlemold form fryer is disposed longitudinally within the fryer and ispositioned above a fryer oil pan 150. Pre-forms are then delivered by abottom entrance conveyer 130 into oil 151 within the fryer oil pan 150for cooking. The pre-forms with proper buoyancy then rise up in the oiland dispose themselves against molding surfaces on the top conveyer 120.U.S. patent application Ser. No. 10/848,881, also assigned to the sameassignee as the present invention, discloses a masa-based dough havingthe proper buoyancy that can be used to make tortilla chips in a singlemold form fryer.

FIG. 2 a is a perspective view of a prior art mold cavity conveyorassembly. FIG. 2 b is a schematic cross-sectional view of the moldcavity conveyor assembly shown in FIG. 2 a. As illustrated in FIG. 2 a,the mold cavities 225 are formed as continuous, longitudinally extending(in terms of the running direction of the belt assembly, indicated byarrow 246), convex-shaped depressions. The mold cavities 225 are curvedabout longitudinally extending axes 244 but, locally, are relativelystraight or non-curved in the longitudinal direction. In other words,the only longitudinal curvature is attributable to the belt flexing, andthat curvature is essentially absent over the length of the portion ofthe belt disposed within the oil pan. The mold cavity elements can beformed from perforated, preferably electro-polished stainless steel. Theperforations should be large enough to allow hot oil to reach theproduct to cook it and for steam to escape. The mold cavity elements 225are fastened 227 together in side-by-side fashion and can be attached tothe top conveyor 120 as shown in FIG. 1 b or to both the top 20 andbottom 30 conveyors as shown in FIG. 1 a. The pre-forms 218 take theshape of the mold cavity 225 as the pre-form is dehydrated in a singleor double mold form fryer.

By using a form fryer, snack foods, such as potato crisps or tortillachips, are capable of being fabricated with a standard and desirableshape. The frying of individual pieces presents numerous difficultiessuch as wrinkling, folding, clumping, and sticking to cooking surfaces.With the use of a form fryer, as opposed to other types of frying, anumber of these difficulties can be resolved.

FIG. 3 a is a perspective view of a prior art snack piece. FIG. 3 b is atop plan view of a snack piece cooked in a form fryer. FIG. 3 c is aside view of the snack piece shown in FIG. 3 a and FIG. 3 b. Referringto FIGS. 3 a-3 c, the snack piece 300 has a length Y perpendicular tothe axis of curvature. The axis of curvature is indicated by thedirection of the arrow 348. The snack piece 300 has a centerline 310parallel to the axis of curvature located along a balance line 325,located away from the center line 310. As shown in FIG. 3 c, the snackpiece resting on a flat surface will naturally balance about thecentroid 320. In the case of an asymmetrical shape, the centroid 320 islocated away from the centerline 310. As a result, the snack pieceproduct edge labeled as the apex A can attain a first height H₁, and thesnack piece product edge labeled as the base B can attain a secondheight H₂, resulting in a height difference. This height difference,however, is undersirable.

FIG. 4 is a cut-away cross-sectional view of a stack of snack pieces218, depicted in FIG. 3 a-c in a snack food container 400. One problemthat arises when stacking prior art asymmetrical snack pieces is thatthe snack pieces need to be oriented in the same direction in order topromote efficient stacking. For example, referring back to FIG. 2 a,adjacent snack pre-forms 218 on each mold are oriented 180 degrees fromone another. Hence, half the snack pre-forms, upon exiting the fryermust be rotated 180 degrees in order to minimize separation (e.g. voidvolume) between the stacked snack pieces 218 when stacked and maximizethe amount of snack pieces that can be placed in a fixed volumecontainer as shown in FIG. 4.

U.S. Pat. Nos. 6,338,606 and 6,409,461 discloses a method and apparatusfor stacking tortilla chips that stacks tortilla chips oriented in thesame direction. It should be noted that the orientation of the snackpieces 218 depicted in the snack food container 400 depicted in FIG. 4are stacked such that the apex A of each chip is adjacent to the apex Aof the chip above and below. Similarly, the base B of each chip isadjacent to the base B of the chip above and below to minimizeseparation between the snack pieces 218. It may be more economical tomake asymmetrical snack pieces that could be stacked withoutre-orientation without reducing the amount of snack pieces (e.g. withoutincreasing void volume) in the snack food container 400. Hence, a needexists for a method to stack asymmetrical snack pieces without areorientation step.

As shown in FIG. 4, the outer radius 405 of a curved snack is greaterthe inner radius 415 due to the thickness of the snack piece. Becausethe inner radius 415 cannot fit around the outer radius 405, the abovechip having an outer radius rests at a distance above the lower chiphaving the inner radius 415. This radius difference creates a separationbetween the stacked snack pieces 218. As previously discussed, chips notpossessing equal mass on either side of the axis of curvature 310 causethe apex A to have a higher height than the base B. Thus, theorientation of this separation may not be linear as additional snackpieces are stacked. For example, although the bottom snack piece 420 isgenerally parallel with the bottom of the snack food container 400, thetop snack piece 440 can be nearly perpendicular to the bottom of thesnack food container 400. This shingling effect is a result of thecumulative height difference (H₁−H₂) depicted in FIG. 3 c. The stackedsnack piece configuration depicted in FIG. 4 can be undersirable as itleads to slack fill of the container. The shingling effect ispotentially magnified through product movement that can occur duringshipping and handling of the product. Further, breakage of snack piecescan more easily occur. Hence, a need exists for a method for making astable, stacked snack piece configuration.

One prior art solution for providing a triangular snack piece that canbe stacked is illustrated by U.S. Design Pat. D452,360S. Unfortunately,FIGS. 2-4 of that design patent illustrate one vertice having a heightgreater than the other two vertices, much like the problem disclosedabove.

Another prior art solution to this problem is illustrated by U.S. PatentApplication 2002/0122852. The '852 Application teaches a containmentwell 12 having a symmetrical spherically shaped radius of curvature (seeFIG. 1 of the '852 application). This configuration, however, fails toteach a method for making a stable, stacked snack piece configurationfor asymmetrical snack pieces. Hence, there is a need for a method formaking snack pieces that can be stably stacked upon one another. Themethod should permit a fried snack piece to have substantially equalheight around product edges when resting upon its centroid. The methodshould be adaptable to various asymmetrical snack piece shapes.

SUMMARY OF THE INVENTION

The present invention provides a method for making a stackableasymmetrical snack piece that can be packaged in a nested or stackedorientation. The snack pieces are made from a mold having at least twoarc lengths integral to the mold. Each arc length has a radius ofcurvature. Based on the desired snack piece dimensions including lengthand height, the arc length and radius of curvature of the mold can becalculated such that when the dough piece is registered with the mold,each vertice of the dough piece will have a substantially equal heightwhen resting upon a flat surface after the dough piece has been cookedin the mold. The dough piece takes the form of the mold as the doughpiece is cooked into a snack piece. The resultant snack piece can thenbe efficiently stacked.

In one aspect, the mold comprises a method for making an asymmetricalsnack piece with a symmetrical mold that does not require re-orientationprior to being stacked. The above as well as additional features andadvantages will become apparent in the following written detaileddescription.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the invention are setforth in the appended claims. The invention itself, however, as well asa preferred mode of use, further objectives and advantages thereof, willbe best understood by reference to the following detailed description ofillustrative embodiments when read in conjunction with the accompanyingdrawings, wherein:

FIG. 1 a is a schematic cross-sectional view of a double mold form fryerwith continuous top and bottom conveyors.

FIG. 1 b is a schematic cross-sectional view of a single mold form fryerwith a continuous top conveyor.

FIG. 2 a is a perspective view of a prior art mold cavity conveyorassembly.

FIG. 2 b is a schematic cross-sectional view of the mold cavity conveyerassembly shown in FIG. 2 a.

FIG. 3 a is a perspective view of a prior art snack piece.

FIG. 3 b is a top plan view of a prior art snack piece.

FIG. 3 c is a side elevational view of a prior art snack piece.

FIG. 4 is a cut-away cross-sectional view of a stack of snack piecesdepicted in FIGS. 3 a-c.

FIG. 5 a is a side elevational view of an asymmetrical mold andresultant snack piece made by one embodiment of the present invention.

FIG. 5 b is a side elevational view of a portion of FIG. 5 a furtherdepicting an angle and a radius of curvature.

FIG. 5 c is a side elevational view of a portion of FIG. 5 a furtherdepicting a first radius of curvature and a second radius of curvature.

FIG. 5 d is a side elevational view of an asymmetrical mold andresultant snack piece made by one embodiment of the present invention.

FIG. 6 a is a side elevational view of a symmetrical mold and resultantsnack piece made by one embodiment of the present invention.

FIG. 6 b is a side elevational view of a portion of FIG. 6 a furtherdepicting a first radius of curvature and a second radius of curvature.

DETAILED DESCRIPTION

The present invention, in one embodiment, provides a method for making asnack piece such that when the snack piece is resting upon its centroid,the snack piece edges lie in a plane that is parallel to the restingsurface. The present invention achieves this method by using a moldhaving at least two arc lengths, each arc length having a radius ofcurvature.

FIG. 5 a is a side view depicting an asymmetrical mold and resultantsnack piece shape according to one embodiment of the present invention.Based on the desired resultant snack piece shape dimensions, a mold canbe designed. To properly design the mold, the centroid of the chip mustbe known. The centroid refers to the center of mass of the snack pieceand is dependent upon the shape, size, and density of the snack piece.For example, the centroid of a triangle which is uniformly dense acrossthe shape is the point of intersection of its three medians. A median isa line joining each vertex to the midpoint of the opposite side. Thecentroid of a more complex shape can be calculated by a computer programsuch as AutoCad®, available from Autodesk of San Rafael, Calif. Based onthe centroid location, the minor distance W can be calculated. As usedherein the minor distance W is defined as the shortest distance,perpendicular to the desired axis of curvature, from the centroid toeither of the two chip edges.

FIG. 5 b is a side view depicting variables used to calculate a radiusof curvature R according to one embodiment of the present invention. Asshown, the FIG. 5 b comprises known values of desired chip height H,total chip length Y, and minor distance W. With these known values, anangle θ_(r) (radians) can be calculated using, for example, Newton'sMethod of Iteration. From the calculated angle θ_(r), a first radius ofcurvature R can be determined. The mold radius of curvature iscalculated as follows:

First, the arc length S, is calculated from equation 1 below.

S=Y−W   [1]

Next, θ_(r) can be calculated with the help of Newton's Method ofIteration and equations from geometry. For example, from FIG. 5 b, it isknown that:

2*H/S=(1−cos)(x))/x   [2]

-   -   where

θ_(r)=2x, or   [3]

x=θ_(r)/2

For an initial guess, we can assume that:

k=H/S   [4]

x(0)=2*k   [5]

Then, applying Newton's Method of iteration, values of x can becalculated until the desired convergence is achieved. Thus,

x(n+1)=x(n)−cos(x(n)+k(x(n)−1)/(−sin(x(n)+k)   [6-A]

Thus, for the first iteration,

x(1)=x(0)−cos(x(0)+k*(x(0)−1)/(−sin(x(0)+k)   [6-B]

Once the desired convergence for x is achieved, θ_(r) can be calculatedfrom equation 3 above. Equation 3 above indicates that θ_(r)=2x. Thus, amold radius of curvature R can be calculated from equation 7 below.

R=2*S/θ_(r)   [7]

The above formulas can be input into a spreadsheet algorithm to simplifythe calculations.

The above invention will now be described with reference to an example.The example below illustrates the invention for an assymetric moldhaving only two radii of curvature. It should be noted that more radiiof curvature will produce a more uniform mold.

EXAMPLE

FIG. 5 c is a side elevational view of a portion of FIG. 5 a furtherdepicting a first radius of curvature and a second radius of curvature.Using a desired chip length Y of 3 inches having a desired chip heightof 0.5 inches and a minor distance of 1 inch, we have the following:

Y=3 inches

W=1 inch

H=0.5 inches

From equation [1] above, we know that S1=Y−W, or that the first arclength S1 is 2 inches. Next for an initial guess for Newton's method ofiteration used to first to calculate an angle, then a radius ofcurvature, equation [4] indicates that k=H/S1 or that k=0.5/2 or thatk=0.25. Equation [5] indicates that x(0)=2*k, or 0.50. Applying Newton'smethod of iteration to equation 6 above results in the following:

x(1)=(0.5)−(cos(0.5)+0.25*0.5−1)/(−sin(0.5)+0.25), which reduces to

x(1)=0.511257

By similar methods, the following table can be calculated:

x(2)=0.511025

x(3)=0.511025

x(4)=0.511025

Then, solving equation 3 for θ_(r1) reveals thatθ_(r1)=2(0.511025)=1.022049. Next, equation 7 can be solved to determinethe mold radius of curvature, which is R=2*2/1.022049. Thus, the moldradius of curvature is 3.913705.

The next step is to then solve for the second radius of curvature. Thesecond arc length S2 is equal to the minor distance of W. Thus, we havethe following:

Y=3inches

W=1 inch

H=0.5 inches

S2=1 inch

Next for an initial guess for Newton's method of iteration used to firstto calculate an angle, then a radius of curvature, equation [4]indicates that k=H/S2 or that k=0.5/1 or that k=0.50. Equation [5]indicates that x(0)=2*k, or 1.0. Applying Newton's method of iterationto equation 6 above results in the following:

x(1)=(1.0)−(cos(1.0)+0.5*1.0−1)/(−sin(1.0)+0.50), which reduces to

x(1)=1.118026

By similar methods, the following table can be calculated:

x(2)=1.109188

x(3)=1.109144

x(4)=1.109144

Then, solving equation 3 for θ_(r2) reveals thatθ₂=2(1.109144)=2.218288. Next, equation 7 can be solved to determine themold radius of curvature, which is R2=2*1/2.218288. Thus, the secondradius of curvature R2 is 0.901596.

The junction where the first arc length and second arc length cometogether can be abrupt. Hence, it may be desirable to smooth out themold by providing a plurality of arc lengths, each having a radius ofcurvature. FIG. 5 d is a side elevational view of an asymmetrical moldand resultant snack piece made by one embodiment of the presentinvention. FIG. 5 d depicts a mold having several arc lengths 502 504506 508 510 512 that can achieve a gradual transition while matching thedesired chip length and height. Further, such an embodiment can help tosmooth out pinch points that can be created by placing widely varyingmold radii adjacent one another. For example, in one embodiment, arclength 502 can have a mold radius of curvature that is less than themold radius of curvature associated with the adjacent arc length 504.Similarly, the radius of curvature associated with arc length 504 can besmaller than the radius of curvature associated with arc length 506.Likewise the radius of curvature of arc length 512 can be less than theradius of curvature of arc length 510, which can be less than the radiusof curvature of arc length 508. The more arc lengths that are used witha radius of curvature, the less abrupt the transitions within the moldcan be. In one embodiment, the mold comprises a first end mold radius ofcurvature 502 and a second end mold radius of curvature 512 aresubstantially equal.

In another embodiment of the present invention, the mold can be designedso that the snack piece centroid corresponds to a relatively flatsection substantially in the center section so that the verticaldisplacement between the snack piece centroid and the chip centerline isminimal. Such a configuration can lessen potential cumulative heightdifference potential despite the fact that the centerline of the chipand the product centroid are not the same. In such an embodiment of theinvention, a symmetrical mold can be designed to accommodate a doughpiece having an asymmetrical shape.

FIG. 6 a is a side elevational view of a symmetrical mold and resultantsnack piece made by one embodiment of the present invention. FIG. 6 b isa side elevational view of a portion of FIG. 6 a further depicting afirst radius of curvature and a second radius of curvature. Thecurvature suggested for the center section depends on the overall lengthof the snack piece and the proximity of the centroid to the snack piecemidpoint. One advantage provided by this embodiment of the presentinvention is that the same infeed pattern of snack pieces fed into thefryer can be efficiently nested without reorientation by 180 degreesafter frying because the mold pattern is symmetrical. Thus, an improvednesting efficiency can be achieved.

As shown, the FIG. 6 b comprises known values of desired chip height H,total chip length Y, and minor distance W. With these known values, oneskilled in the art can calculate the proper mold curvatures in aniterative process. It should be noted that different mathematicalformulas than the ones shown above may be required based upon varioussnack piece shapes and the desired number and location of moldcurvatures. In one embodiment, a desired chip length Y of 2.5 inches hada center section radius of curvature of between about 4 to about 5inches. As the mold radius in the center section increases, the chipheight H can increase. Thus, to keep chip height H constant as theradius of curvature of the center section increases the mold radius forthe outside segments may need to be increased to offset any resultantchip height H increase.

It should be noted that various shapes can be used in accordance withthe present invention and the shapes used are limited only by theimagination of those skilled in the art. For example, complex shapes canmimic the outline of a state, such as the state of Texas, or an animal,such as a cheetah, or other object.

A snack piece in accordance with the present invention comprises aplurality of vertices and each of the vertices have a substantiallyequal planar elevation, or height. For example, consider a snack piecemade in accordance with one embodiment of the present invention havingan axis of curvature and having a plurality of vertices. When the snackpiece is resting upon a rigid, flat surface, each vertice will have asubstantially equal distance or height from the vertice to the restingsurface. Thus, the invention provides a method for making a stable,stacked snack piece configuration.

While the invention has been particularly shown and described withreference to a preferred embodiment, it will be understood by thoseskilled in the art that various changes in form and detail may be madetherein without departing from the spirit and scope of the invention.

1.-5. (canceled)
 6. A mold for a form fryer, said mold comprising: afirst section having a first radius of curvature; at least one secondsection having a second radius of curvature integral with said firstsection; wherein said second radius of curvature is smaller than saidfirst radius of curvature.
 7. The mold of claim 6 wherein two secondsections comprise end sections and wherein said first section comprisesa center section disposed between said end sections.
 8. The mold ofclaim 6 wherein said mold is symmetrical.
 9. The mold of claim 6 whereinsaid mold is asymmetrical.
 10. An asymmetrical stackable snack piecehaving an axis of curvature comprising: a centroid, such that when saidsnack piece rests upon said centroid on a flat surface, said flatsurface defines a first plane; and a plurality of vertices, saidvertices defining a second plane, wherein said second plane issubstantially parallel to said first plane.
 11. The snack piece of claim10 wherein said snack piece is asymmetrical about a balance line passingthrough said centroid, wherein said balance line is parallel to an axisof curvature of said snack piece and said centroid is located away froma centerline of said snack piece.
 12. The snack piece of claim 10wherein said snack piece is substantially triangular.